Implement hitch

ABSTRACT

A hitch link structure includes two hitch tubes angled with respect to each other and having forward ends connected by upper and lower hitch plates welded to the tubes. The plates include weld cutouts designed so the same plates can be used with a variety of different hitch tube angles, depending on the width of the mainframe hitch mount-up. Three apertures in the forward end of each of the plates receive bolts which connect the selected hitch link to the plates. The apertures also act as weld fixturing locators to speed hitch construction. The weld cutouts, in generally a half moon configuration, facilitate low cost fillet welds at easily accessible locations regardless of hitch tube angle and facilitate fillet weld connections in relatively lowly stressed areas. The lower plate is apertured to define an intermediate support hole for the safety chain, and the central bolt connecting the hitch link also attaches to the safety chain so the chain is accommodated without additional parts.

BACKGROUND OF THE INVENTION

1) Field of the Invention

The present invention relates generally to pull-type agriculturalimplements and, more specifically, to a hitch for such implements.

2) Related Art

Conventional hitch and hitch link structures presently used on drawnimplements such as chisel plows, field cultivators and seeding equipmentinclude numerous parts and require extensive welding. As a result, thesestructures are relatively expensive to manufacture and are more prone toreliability problems. Further, different implements require differenthitch frame angles and therefore different parts. Different implementmain frame widths on one type of implement require hitch structures ofdifferent dimension. The various fixturing and part requirements for thevarying hitch structures increase the number of parts as well as thecost and complexity of the manufacturing process.

Hitch structures also include safety chain mounting structure. Safetychains are usually attached using a separate set of bolts and a separateplate for intermediate support, thereby further increasing the time andnumber of necessary parts for the manufacture of the hitch structure.

BRIEF SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide animproved hitch link structure. It is a further object to provide such animproved structure that overcomes most or all of the aforementionedproblems.

It is a further object of the present invention to provide an improvedhitch link structure that is simpler and less expensive to manufacturethan at least most previously available hitch link structures. It is afurther object to provide such a hitch link structure that requires aminimum number of parts and which is higher in quality than at leastmost of the previous structures.

It is still another object of the present invention to provide animproved hitch link structure wherein common components can be used fora variety of different hitch tube angles and sizes. It is yet anotherobject to provide such a structure which accommodates a safety chainwithout need for additional components.

It is yet another object of the present invention to provide an improvedhitch link structure including plates for receiving different hitchlinks, the plates including apertures utilized to connect a link andwhich facilitate fixturing for hitch manufacture. It is a further objectto provide such structure wherein one of the plates includes a safetychain intermediate support hole and one of the bolts connecting thehitch link to the plates attaches the safety chain to the hitch.

A hitch link structure constructed in accordance with the teachings ofthe present invention includes two hitch tubes angled with respect toeach other and having forward ends connected by upper and lower hitchplates welded to the tubes. The plates include weld cutouts designed sothe same plates can be used with a variety of different hitch tubeangles, depending on the width of the mainframe hitch mount-up. Threeapertures in the forward end of each of the plates receive bolts whichconnect the selected hitch link, clevis or standard to the plates. Theapertures also act as weld fixturing locators to speed hitchconstruction. The weld cutouts, in generally a U-shaped configurationwith a rounded inner portion and parallel sidelegs embracing thesidewalls of the tubes, facilitate low cost fillet welds at easilyaccessible and relatively lowly stressed locations along the sidelegs,outside the tube, regardless of hitch tube angle.

The lower plate is apertured to define an intermediate support hole forthe safety chain, and the central bolt connecting the hitch link alsoattaches to the safety chain so the chain is accommodated withoutadditional parts. The hitch construction is simpler yet stronger andmore reliable than most previously available constructions. In addition,the components are adaptable to different hitch angles so the number ofparts required for different families of different hitch types issubstantially reduced.

In a second embodiment of the invention, a single hitch tube includes aforward end with opposed sets of walls, and a pair of plates are notchedand received over one set of the walls. Welds adjacent the notched areasconnect the plates with the walls at easily accessible locations. Thehitch link and chain are connected in a manner similar to that describedabove for the hitch which includes two angled tubes, and the single tubestructure has many of the same advantages outlined above.

These and other objects, features and advantages of the presentinvention will become apparent to one skilled in the art upon readingthe following detailed description in view of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of the link mounting plate area of animplement hitch showing a first hitch tube angle (solid lines) and adifferent hitch tube angle (broken lines).

FIG. 2 is a top perspective view of the link mounting plate area of animplement hitch having a single hitch tube.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring now to FIG. 1, therein is shown the forward portion of animplement 10 such as a field cultivator or chisel plow. The implement 10includes hitch structure 12 for connection to a towing vehicle (notshown) such as a tractor for forward movement (F) over the ground.

The hitch structure 12 includes two forwardly converging hitch tubes 16and 18 with forward ends 26 and 28 having rectangular cross sectionsincluding parallel top and bottom walls 30, 31 and 32, 33 connected bysidewalls 36, 37 and 38, 39. The forward ends 26 and 28 are supportedwith the top walls 30 and 32 lying in a first plane and the bottom walls31 and 33 lying in a second plane offset from and parallel to the firstplane. The aft ends (not shown) of the hitch tubes 16 and 18 extendrearwardly to connections with the implement frame, and the angle of thetubes 16 and 18 relative to each other is dependent on the implementsize and type.

The forward ends 26 and 28 are supported between first and second plates42 and 44 secured to the top and bottom surfaces, respectively, of thewalls 30, 32 and 31, 33. A hitch link 46 is connected between the plates42 and 44 at a central location adjacent the forward ends 26 and 28.

The hitch plates 42 and 44 include identical notches 50 and 52 openingrearwardly in the direction of the length of the tubes 16 and 18 (onlythe notches for the plate 42 are shown but the notches for the plate 44are similarly shaped and located). The notches 50 and 52 are U-shapedwith the sidelegs of the U being parallel and extending over the topwalls 30 and 32 and under the bottom walls 31 and 31 inwardly from therespective sidewalls. The bight portion of the U-shaped configuration isgenerally semicircular. The configuration and location of the notches 50and 52 accommodates a variety of hitch tube angles (see, for example,the broken lines of FIG. 1) while retaining the legs of the U-shapedconfigurations adjacent the respective walls 30-33 without interruption.Edge portions 56 and 58 of the notches 50 and 52 are welded rearwardlyof the semicircular portion of each notch along the sidelegs. Theresulting fillet welds are strong and in easily accessible locations forimproved manufacturability. High stress areas around the semicircularportions remain unwelded to reduce or eliminate incidences of stresscracks and improve reliability. Because the notches 50 and 52 alignproperly with the top and bottom walls of the hitch tubes for manydifferent tube angles, the same plates 42 and 44 can be utilized for avariety of hitch types and implement sizes.

As shown in FIG. 1, forward central portions of the plates 42 and 44 areapertured to receive bolts 61, 62 and 63 which extend throughcorresponding apertures in the hitch link 46 to secure the link betweenthe plates forwardly of the tubes 16 and 18. In addition to receivingthe bolts 61-63 which secure the hitch link 46, the apertures in theplates 42 and 44 provide fixturing locations during manufacturing.

The lower plate 44 includes a rectangularly shaped opening 70 outwardlyof the forward end 28 of the tube 18 to provide intermediate support fora safety chain 72. One end 74 of the chain is secured to the hitchstructure by the bolt 61 and a nut 76 and large washer (not shown). Anopposite end 78 of the chain is connected to the towing vehicle. Makingthe chain support integral with the hitch plate and using the hitch linkconnecting bolt to secure the chain reduces the number of necessaryparts and the cost of manufacturing.

In another embodiment of the invention (FIG. 2), a hitch structure 82includes a single fore-and-aft extending tube 86 of rectangular crosssection with top and bottom walls 90 connected by sidewalls 92. The tube86 has a leading end 96 opening in the forward direction (F). Theleading end 96 defines a tube edge 98 which generally lies in an uprightplane. First and second plates 102 and 104 are secured to the leadingend 96 and support a hitch link 106 adapted for attachment to a towingvehicle. A safety chain 108 is supported by the hitch structure 82.

The first or upper plate 102 includes rearwardly opening notches at 112which are transversely spaced a distance approximately equal to thedistance between the sidewalls 92, and the width of the notches isslightly larger than the width of the sidewalls 92. The notches at 112include sides which extend parallel to each other and parallel to thesidewalls 92. The second or lower plate 104 includes rearwardly openingnotches at 114 which are spaced and configured generally identically tothose at 112 in the plate 102.

The first plate 102 is positioned in the leading end 96 with the sidesof the notches at 112 embracing the inner and outer surfaces of thesidewalls 92. Fillet welds at locations 118 and 120 between the upperportions of the outer sides of the notches at 112 and the outer surfacesof the sidewalls 92 secure the plate 102 to the tube 86 in slightlyoffset, parallel relationship with the top wall 90. The four weldlocations are easily accessible and provide a strong, reliableconnection of the plate 102 with the tube 86. Welds at extremely highlystressed areas of the plate 102 are avoided. Similarly, the plate 104 ispositioned in the leading end 96 below and parallel to the plate 102,offset slightly above the bottom wall of the tube 86. The sides of thenotches at 114 embrace the sidewalls 92, and fillet welds are providedat locations 122 and 124 in a generally identical manner to the welds118 and 120 for the plate 102. Again, the weld locations are easilyaccessible and provide a strong, reliable connection between the plate104 and the tube 86.

Bolts 131, 132 and 133 extending through aligned holes in the plates 102and 104 and through corresponding holes in the hitch link 106 secure thehitch link in a central, forward position relative to the leading end 96of the tube 86. The leading side of the lower plate 104 is apertured at140 to provide an intermediate support for the chain 108. One end of thechain 108 is connected to the bolt 131 with a nut 146 and a large washer(not shown).

Having described the preferred embodiment, it will become apparent thatvarious modifications can be made without departing from the scope ofthe invention as defined in the accompanying claims.

What is claimed is:
 1. In an implement adapted for connection to atowing vehicle for forward movement over the ground, hitch structurecomprising: first and second hitch tubes converging in the forwarddirection at an angle relative to each other depending on implementsize, the hitch tubes having forward ends in close proximity to eachother, the forward ends including upper and lower surfaces extendinggenerally parallel to each other; an upper plate extending between thetubes over the upper surfaces; a lower plate extending between the tubesbelow the lower surfaces; the plates having notched configurationsincluding notches with sides located adjacent the upper and lowersurfaces and a rounded portion connecting the sides; and weldsconnecting the sides of the notches with the upper and lower surfaces,wherein the rounded portions are substantially free of welds.
 2. Thehitch structure as set forth in claim 1 wherein the notches align withthe surfaces over different preselected angles to facilitate weldedconnections of the hitch tubes at the different angles so that thepreselected configurations can be utilized to manufacture hitches fordifferent implement sizes and types.
 3. The hitch structure as set forthin claim 2 wherein the notches open rearwardly and the sides extendgenerally in the direction of the hitch tubes.
 4. The hitch structure asset forth in claim 1 wherein the plates are apertured, and including ahitch link connected by bolts extending through apertures in the plates,wherein the apertures provide fixturing locations for the hitchstructure during manufacture of the hitch structure.
 5. The hitchstructure as set forth in claim 1 wherein one of the plates includes anaperture, and further including a safety chain received in the aperture.6. The hitch structure as set forth in claim 1 wherein the plates areconnected to the forward ends exclusively by welds extending between theplates and the top and bottom surfaces.
 7. In an implement adapted forconnection to a towing vehicle for forward movement over the ground,hitch structure comprising: first and second hitch tubes converging inthe forward direction at an angle relative to each other depending onimplement size, the hitch tubes having forward ends in close proximityto each other, the forward ends including upper and lower surfacesextending generally parallel to each other; an upper plate extendingbetween the tubes over the upper surfaces; a lower plate extendingbetween the tubes below the lower surfaces; the plates havingpreselected configurations including notches with sides located adjacentthe upper and lower surfaces; welds connecting the sides of the notcheswith the upper and lower surfaces; wherein one of the plates includes anaperture, and further including a safety chain received in the aperture;and a bolt connecting the hitch link to the plates, and wherein the boltalso connects the safety chain to the plates so that the safety chain isconnected to the plates without need for additional connecting hardware.8. In an implement adapted for connection to a towing vehicle forforward movement over the ground, hitch structure comprising: first andsecond fore-and-aft extending hitch tubes converging in the forwarddirection at an angle relative to each other depending on implementsize, the hitch tubes having forward ends in close proximity to eachother, the forward ends including surfaces generally lying in a plane; aplate positioned against the surfaces and extending between the hitchtubes, the plate including a rearward portion having notches opening inthe rearward direction adjacent the surfaces, the notches includinginner rounded portions and generally parallel sidelegs extendingrearwardly from the rounded portions; and welds connecting the plate tothe surfaces, the welds extending generally in the fore-and-aftdirection between portions of the notches adjacent the parallel sidelegsand the surface and wherein the rounded portions are substantially freeof welds.
 9. The hitch structure as set forth in claim 8 wherein theplate includes an apertured portion, and a hitch link connected to theplate by bolts extending through the apertured portion.
 10. The hitchstructure as set forth in claim 9 wherein the notches align with thesurface over different preselected angles to facilitate weldedconnections of the hitch tubes at the different angles so thatsubstantially identically configured plates can be utilized tomanufacture hitches having different hitch tube angles.
 11. The hitchstructure as set forth in claim 8 wherein areas of the plate along therounded portions of the notches comprise highly stressed areas and arecharacterized by the absence of a weld in the highly stressed areas. 12.In an implement adapted for connection to a towing vehicle for forwardmovement over the ground, hitch structure comprising: first and secondfore-and-aft extending hitch tubes converging in the forward directionat an angle relative to each other depending on implement size, thehitch tubes having forward ends in close proximity to each other, theforward ends including surfaces generally lying in a plane; a platepositioned against the surfaces and extending between the hitch tubes,the plate including a rearward portion having notches opening in therearward direction adjacent the surfaces, the notches including innerrounded portions and generally parallel sidelegs extending rearwardlyfrom the rounded portions; welds connecting the plate to the surfaces,the welds extending generally in the fore-and-aft direction betweenportions of the notches adjacent the parallel sidelegs and the surface;wherein the plate includes an apertured portion, and a hitch linkconnected to the plate by bolts extending through the apertured portion;and a chain connected to one of the bolts and extending through anopening in the plate.